Seventy years after the first two-way radio was fitted in a Chicago police car, a revolutionary new system is linking Cape Town’s emergency services
David Shapshak
The City of Cape Town last week launched the first digital public radio system in Africa, which seamlessly connects all public safety departments into one secure, high-speed network. Bringing with it a host of remarkable features, this revolutionary new system, called TErrestrial Trunked RAdio (Tetra), can send mugshots of suspects as well as let police officers talk to all other emergency service personnel in a crisis.
While all separate services have their own “channel” they can be “patched” through to any others, or to all services simultaneously should there be a need to assist at the scene of a crime or a disaster.
The system, running on Motorola infrastructure and handsets and installed by South African communications company Alcom, can also prioritise calls during an emergency, letting key calls through instead of low-level maintenance conversations previous radio systems afforded all users the same status.
This unprecedented connectivity has numerous advantages. Chief among these is that the system uses trunking, or the ability to pool radio frequency resources. Thus, while users draw resources when they make a call, these are returned to the pool when the call is finished.
As each handset has its own digital identity, the system can be used as a standard radio network, where all users hear anyone within their group, or to make a private call, much like a phone call, by “dialling” another handset directly.
Power users on the system, such as supervisors or operators of the centralised control centres, can swop easily between groups. Police in the city centre, for instance, will use one channel, while those operating outside this zone will use another. In the event of a crime or pursuit, all the channels can be linked so that all officers can hear what their colleagues are doing.
The Motorola handsets also have some cellular-like functionality, which allow users to make regular phone calls. Obviously such privileges will be restricted to supervisors or users who require them.
Tetra’s digital nature is a giant leap forward for law enforcement agencies and public safety operations in general.
“Digital expands your capabilities,” says Eike Br, Motorola’s corporate vice-president responsible for its radio business in 22 countries. “It allows you to add applications that police and safety guys have been desperate for.”
For example, you can track and control the location of vehicles, as the system shows control centres where the individual handsets are on the city grid.
“You can manage a system more efficiently. Higher efficiency means you can do more with fewer officers. That’s a big advantage,” he says, adding that police in Warsaw have had major success with a similar system.
The system can also transmit voice and data information simultaneously. This means that police officers can be sent fingerprints or registration details of suspected stolen cars that they have requested during a voice call, without losing the call.
“This has a very fast reaction time. In seconds the officer has feedback from the database if the car is stolen,” says Br.
Short messaging, such as SMS on cellphones, makes it possible for a doctor to be notified by text message of an emergency while he is on a call.
Additionally, the control centre will have more “intelligence” about the situation on the ground. Given the radio’s digital data capabilities, you could even add digital cameras and let controllers see the actual scene, Br adds. “This expands the possibilities of radio in public safety dramatically.”
Tetra’s launch is part of Cape Town’s Unicity integration project, but should be seen against the backdrop of global initiatives to enhance the operational efficiency of public safety services in general. It is one of just 30 such systems in the world, including one that will be used by South Korean police at this year’s football World Cup.
In South Africa it is also part of a process to rationalise the airwaves, in as much as it coincides with a national drive to streamline the many municipalities.
All municipalities and their various departments (electricity, water, sewerage) require radio frequencies to operate, resulting in a proliferation of separate channels and inefficient use of the radio waves, which are a scarce resource.
Thus, the SA Band Replanning Exercise (Sabre) was formed to rationalise the reissuing of spectrum in South Africa, says Carl Schneider, the City of Cape Town’s head of electrical engineering.
Local authorities will be required to migrate to the 410Mhz to 430Mhz portion of the bandwidth by the end of the year.
Cape Town has been praised for its achievements. Aside from rationalising the numerous municipalities and their operations into the Unicity, Tetra must cover a 4419km2 area and the 3,1-million people who call it home; while coping with the mountains that divide the Cape peninsula.
Belinda Walker, Cape Town’s deputy mayor, says the new system is part of its “smart city” and “well-run city” objectives. “The installation of this network plays a significant role in the transformation of the city into one administration,” she said at the launch.
“Integrated radio communication is an essential component of effective service delivery to the citizens of Cape Town. Radio communication is vital for the efficient operation of emergency and municipal services, and the installation of a new digital trunked radio system will meet the needs of the recently unified city well into the future.”
Approximately 2500 City of Cape Town staff are already using the system and the city aims ultimately to have 5047 users. The cost of the infrastructure is put at approximately R55-million, while the handsets themselves add another R50-million.
However, as one of the officials involved pointed out, the system will pay for itself in five to eight years. This is because the old radio system had proved so inefficient that the city had resorted to using cellphones as an interim solution, but they were not suited to this environment. They only communicate one-to-one and are very expensive “status symbols”.
“We were looking at cheaper solution in the long run than cellphones, which were used in the interim,” says Schneider.
Tetra has a low operating cost about R100 a month for each handset and no “call” costs over the radio frequencies.
The Tetra handset is much more suited to the hard-wearing requirements. The handset for supervisors looks like a chunky cellphone, while that for general use is “ruggerdised” with a hard plastic casing that is splash proof and shock resistance, while its rotary dials can be used by personnel wearing gloves. The battery is designed to last a whole shift. It also has a standardised data connector so that third-party applications such as one to deliver fingerprints to a patrol car can easily be added.
Each handset is also equipped with an emergency button on the dispatcher’s console, which flashes red to alert all users in a group of an officer in danger, for example.
And while it may be one of the less important technical features, the fact that the system is digital and therefore encrypted means that tow-truck drivers will not be able to listen in clearly an emotional triumph for both emergency services personnel and the public over the “vultures” of car accidents.
Ridwan Magiet, the manager of the closed-circuit TV radio control room, which uses cameras in parts of the city to monitor potential criminal activity and is one of the Tetra dispatch centres, says: “Tow-truck drivers seem to think they are emergency vehicles, but they are really recovery vehicles.” The new system, he believes, will force the towing industry to become more organised and avoid the all-too-common haggling between drivers at accidents over who got there first and therefore who tows the accident vehicle.
Another advantage of Tetra is that if accidents occur outside the network the handsets can still function using direct mode operation, which enables personel to talk directly to each other. As Tetra is a global standard, it is “interoperable” with other manufacturers’ handsets.
“It will enhance the safety not only of residents, but of emergency personnel themselves,” says Hugh McCluskey, the group executive for manufacturing from Alcom’s parent company Altech. He adds that Cape Town has “crossed the digital divide” and “can be proud to consider itself a leader”.
Indeed, Tetra solves the myriad communication problems any city faces and it is hoped that the Cape Town example will prove fruitful for other cities and their public safety officers.
This digital system may not be as much of a giant step forward as the 1930s innovation that gave Chicago policemen a return path to talk to the city’s control room, but it is a significant leap in the right direction for South Africa’s beleaguered emergency services.